sawyer



'To all whom it may concern;

, Ares i; Fare-Ea WI LIAM 1. sAwrER, on NEW YORK, AND LBoN MAN, OF BRooKLYn, n. Y.,.AssIoNons TO ELEC'IRO DYNAMIC LIGHT confirm? CARBON FOR ELECTRiC LIGHTS.

SPECIFICATION iol'ming part of Letters Patent No 229,335., dated June 2-9., 13,570

Application filed Novemherll, 1878. I 1- Be it known that we, WILL'rAM EDWARD SAWYER, of the city, county, and State of New York, and ALBoN MAN, of Brooklyn, county of Kings, and State aforesaid, have jointly-inyented certain Improvements in Oarbons for, Electric Lights; and we do hereby declare the Pfollowing to be a descriptiuip of thesame, and

of the manner and process of making, constructing, and usmg them, in such full, clear, concise, and exact terms as will enable any person skilled in the art or science to which it appertains, or with which it is most nearly connected, to make, construct, and use the same, reference being had to certain Letters Patent of the United states heretofore granted to us for certain inventions hereunto appertaining, and to which especial reference will hereinafter be made.

.Our invention consists of a new article of manufacture, consisting of an improved illu minating conductor for electric lamps, composed of consolidated carbon created by elec tric action.

' In Letters Patent of the United States No.

'bon. In most of such carbon't-hereis dangerof fracture as well as of the establishment of thevoltaic arc; and, furthermore,the carbon,- unless specially prepared by our process, naturally occludes sufficient air or-oxyg-en to render its consumption a more question of time,

sincc,'as fully set forth in the Letters Patent referred to, the least quantity of oxygen in a sealed lamp is snfiicient t0 combust an indefinite quantity of carbon.

' As is' wiell known, carbon suit-able for elec tric lighting by the voltaic arc ,is naturally;

produced in gas-retorts; but generally the rods b1 carbons used in the regulatorlamps, socalled,..are molded fronrthe powdered material. Neither the one nor the other quality of carbon is Senate for eleotriqlignting by incan'descence. In both their? is a lack of homoand dense, because, in-the first place, the heat.

required to produce the proper character of carbon is as high as 7,000" Fahrenheit, and such .a temperature is not obtaipablei n? the retort; and in thesecond place the mechanical subdivisions of the material and the pressure geneity. The :pencil-isimt s-rniiciicntly hard necessary to produce the perfect article are practically unattainable; Carbon of the ordi-,

nary sort, when heated by the-electric current, exhibits point-s a'nd'liues of unequal brilliancy. Carbon prepared by our process,when so heated, glo\vs with 'a uniform brilliancy throughout.

We have foundtllat a pencil of carbon immersed in a'hydrocarbon gas or, liquid and heated to'an' extremely high temperature by the voltaic'current is not itself attacked, but decomposes the surrounding matter, the carbon of which enters and fills up its pores to an extentimpossible except with matter in'a very attenuated state, and deposits a perfectly homogeneous layer, generally of a bright carbon increases in size more current is required to maintain its temperature, and ifthe current is gradually increased in accordance with the demand for itthere is appearingly no limit to. the increase in mass of the homo- "geneous exterior deposit. Carbon pencils may be cut from thisdeposit, or the original pencil with its coating may be used in the lamps. In this process it would seem that the can hon is neverin contact with the liquid in which it is immersed, but surrounded by a carbon gas of a veryhigh temperature. 'Naphtha, turpentine, beeswax, balsam, and most oils,

if pure, operate satisfactorily. Almost any hy-- drocarldon, 1n fact, will answer.

\Ve do notconfine ourselves to tne treat-g ment of carbon alone, since it is obvious that many iul'usible substances, nonconductors of electricity, may be heated in hydrocarbon liquids or gases, so as to render them conductors of electricity as, for instance, a tube .of.-lime inclosing apencil of carbon, through which the electric current is caused to circulate.

In the Letters Patent hereinbefore referred to we ha e described a method of charging a 100 gray color, upon the exterior surface. As the 9 suppose that the'pencil of carbon, held between two carbon pieces of greater mass thanthat of the pencil, as shown in the said Letters Patent, is immersed in the hydrocarbon liquid and heated in the manner already described. Being then cleansed in alcohol, the pencil and its holders, without having been disturbed, are placed in the glo e, in which bonaceoussubsta-nce; is charged with pure nitrogen, and then, while 1 tric burners..-

still allowing pure nitrogen to flow into and 1 they are to be hermetically sealed. The globe out of the globe, we heat the carbon to incandescence, thus driving out all impurities and occluded gases, which are carried out of the lamp by the current of nitrogen.

\Vilh this operation the preparation 01 he carbon is completed, and the lamp, now-being hermetically sealed, as described in the Letters Patent referred to, ismpaidy for use.

Having thus described our invention, we claim and desire to'secure by Letters Pa'tenttrieally treating it, in combination with a carter the production of elec- WILLIAM EDWARD V SAWYER. ALBON MAN," Witnesses: Autos BROADNAX, THOS. CRocKEmf Carbon consolidated purified by elec- 

